test: build before running the tests + add js file extension in the imports

Author: aminya

package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "main": "lib/index.js",
   "scripts": {
-    "test": "mocha --recursive test/ --timeout=0",
+    "test": "npm run build && mocha --recursive test/ --timeout=0",
     "report": "npx c8 npm test",
     "coverage": "npx c8 --reporter json npm test && npx codecov -f coverage/coverage-final.json",
     "install": "node installer.mjs",

src/createSfx.ts

@@ -1,11 +1,11 @@
 'use strict';
 
-import { createArchive } from './index';
+import { createArchive } from './index.js';
 import when from 'when';
 import { fileURLToPath } from 'url';
 import { dirname, sep, join } from 'path';
 import fs from 'fs-extra';
-import { Binary } from './utility';
+import { Binary } from './utility.js';
 import { isWindows } from 'node-sys';
 const platformTitle = {
     win32: 'Windows OS',

src/index.ts

@@ -1,8 +1,8 @@
 'use strict';
 
 import when from 'when';
-import { Files, ReplaceNativeSeparator, Run } from './utility';
-import { createSfx } from './createSfx';
+import { Files, ReplaceNativeSeparator, Run } from './utility.js';
+import { createSfx } from './createSfx.js';
 import { isWindows } from 'node-sys';
 
 function retry(